Metal scaffolding



1942- N. 5. BLACK METAL SCAFFOLDING 2 Sheets-Sheet 1 Filed March 13,1940 INVENTOR. fi/a 6T fi/QM u i in.

DeQ 1942- N. 5. BLACK 2,303,428

METAL SCAFFOLDING Filed March 13, 1940 2 Sheets-Sheet 2 'INVENTOR.

ATTO Y. l

Patented Dec. 1, 1942 UNlTED'STATEfi PATENT OFFICE.

2,303,428 METAL SCAFFOLDING Nolan s. Black, Detroit, Mich. ApplicationMarch 13, 1940, Serial No. 323,758

8 Claims.

This invention relates to metal scaffolding of the type composed of aseries of interchangeable elements which can be assembled incombinations which will meet the scaffolding requirements under amajority of all types of Working conditions. i I One object of thisinvention is to achieve great adaptability or flexibility with the useof a fewer number of structural elements, as distinguished from previousscaffolds of this general character.

Another object is to permit the independent assembly and disassembly ofthese elements, or in other words, to permit any one element to beplaced in position or removed from such position without affecting thestructural relationship of adjacent elements.

Incidental to this object is a further object, namely, to design theseelements so that their interengagement depends to the greatest possibleextent upon interlocking surfaces rather than machine elements which areeasily lost and misplaced.

Another object is to produce a scaffold composed of a series oftriangular sections, thereby incorporating in such scafiold thewell-known rigidity and strength of the structural triangle.

A further object is to construct elements having low weight, so thatthey may be easily and safely assembled by one or two men, and at a costwhich will favorably compare with that of non-permanent woodenscaffolds.

Other objects and advantages, of lesser importance, will appear after astudy of the following description of the invention, as supplemented byreference to the accompanying drawings, in which:

Fig. 1 is an elevation of the essential elements of the scafi'old inassembled relation.

Fig. 2 is a plan view of the same.

Fig. 3.is a section taken along the line 33 of Fig. 1.

Fig. 4 is a section taken along the line 4-4 of Fig. 1.

Fig. 5 is a side view of a sleeve-like element adapted to retain thehorizontal members in position.

Fig. 6 is a side view of a foot upn which the upright members rest.

Figs. 7 and 8 are views of different types of upright members orextensions thereto.

Fig. 9 is a plan view showing floor sections assembled in thescafiolding.

Fig. 10 is a section taken along the line 10-1 0 line 'Il--,ll 'of Fig.9, both showing details of this floor construction.

Fig. 12 diagrammatically shows the manner in which the scaffold isassembled in order to have it conform to a curving wall.

Fig. 13 illustrates vthe manner in which the elements of the scaffoldingmay be assembled in an arch construction.

Fig. '14 is an elevation'showing the scaffolding elements assembled toform the base of a tower.

Fig. 15 is a plan View of the structure in Fig. 14.

Fig. 16 shows an alternate form of the manner in which horizontalelements may be assembled to the vertical members.

The scaffolding of the present invention is supported froma series ofupright posts such as the post 2| or the post 22, an alternate form usedwhereit. isnecessary to compensate for unevenness of the ground uponwhich the scaffold is to be erected. Deferring for the present, thediscussion of. the post 22, the post 2| is .constructed of a length ofsquare tubing, to the lower end of which is welded a filler member 23,adapted to fit snugly within the foot or standard 24, shown inFig. 6, orthe upper end of any other upright member such as the end of themember'ZB shown in Fig. 7. These posts are connected by a series ofhorizontal braces comprising the brace 2'! and two other similar braces28 and Y29 of equal length but shorter than the brace 21, portions ofthese latter two braces being shown in dotted lines in Fig. 2; and thecombination of these three braces is such that the resultant distancesbetween the center lines of any three posts to which they are connectedform a right angle isoceles triangle, in which the two shorter braces 28and '29 are the legs and the brace 21 the hypotenuse. This constitutesthe basic element of the scaffolding, although other combinations arepossible according to the nature of the work to be done. Each braceconsists of a pair of vertical tubular members connected andtriangulated by the members 3| to a horizontal member 32,.and while therespective sizes of these members may be varied .within wide limits, theessential requirement and feature of the present construction is thateach successive size of cross brace should bear to the next smaller sizeof brace the approximate relation of a hypotenuse of a right angleisosceles triangle, the legs of which are composed of such next smallersize of brace, or in other words, the length of each successive size ofbrace is substantially equal to the length of the next smaller of Fig. 9and Fig. 11 is a section taken along the 5 size of brace divided by sinBy keeping the sizes of the horizontal braces in this relation, a widerange of scaffold structures is obtained with a minimum number ofelements of different sizes and it is also thus possible to usetriangulated combinations of all sizes of elements in the same system ofscaffolding, in constructing such scaffolding to the dictates of eachparticular structure.

The flexibility of the present type of scaffolding arises principallyfrom the manner in which the braces are attached to the uprights. Acircular plate 33 is welded to the post 2| approximately midway its endsand is provided with a series of holes 34 adapted to receive the lowerends of the tubular brace members 30. Another similar plate 35, havingholes 36, is welded to a sleeve 3! which slips over the upper end of thepost or upright which is provided, as can be seen from the uprights inFigs. 7 and 8, with a hole 38 and a slot 39, and in attaching thissleeve to the post a bolt 49 is inserted through the hole 4| in thesleeve and the slot 39 in the post, thereby permitting a limitedvertical movement of the sleeve such that when in its upper position theplate 35 is not quite raised above the upper end of the tubular member30 of the brace 21. When the sleeve is in this upper position, thebrace, therefore, is still secured to the post 2|, but it can be readilydetached therefrom by'simply lifting the lower end of the tubular member30 out of engagement with the lower plate 33, and then by swinging thislower end so as to clear this plate, the brace can be lowered until theupper end of the tubular member is withdrawn from the upper plate 35.Thus, when a plurality of braces are attached to one upright by a pairof plates, any one of them may be removed without disturbing thestructural relationship of the others, and likewise, an additional bracemay be included without affecting those already in place. In order tofacilitate the assembly of the horizontal and vertical members, andbecause of the fact that the horizontal braces are pivotally mountedbetween the fastening plates and thus free in a limited sense to rotateabout the posts, a short channel section 63 is welded to the peripheryof the upper plate 35 adjacent one of the holes therein to serve as'anindex to prevent rotation and retain any brace which may be connected tothe post, through this adjacent hole in the plate 35, in its normallycorrect position. As soon as the desired number of braces are inposition, the sleeve "3''! may be locked in its lower position byinserting a bolt through the then aligned holes 42 and 3B in the sleeveand post respectively. When the vertical member is extended by the useof another similar post or either of the posts 26 and 43 shown in Fig. 7and Fig. 8 respectively, such post will be secured in position by thissame bolt passing through the holes 44 in the filler member '23 of suchpost.

These posts 26 and 43 are constructed so that their combined length isequal to that of the standard post 2 l, and therefore the two posts canbe used in place of any one of the longer posts; with the added featurethat thereby greater horizontal bracing can be obtained wherever neededby reason of the design of the post 43 which is also provided with aplate 33, attached at a point adjacent its lower end. This combinationof posts is used in erecting the structure shown in Fig. 13.

The adjustable post 22 is composed of a large jack screw 46, having acollar 41 mounted at its midpoint, and provided with right and left handthreads extending either side of this collar. This jack screw iscontained within the post which is divided into two sections 48 and 49,to the adjacent ends of which are attached jack screw nuts 59 and 5|which are engaged by the threaded portions of the jack screw so thatwhen it is revolved by inserting a bar in the hole 52 of the collar 41the sections 48 and 49 will either move apart or be brought together,depending upon the direction of rotation. If the jack screw isconstructed of a length of suitable tubing rather than of solid stock,the total weight of the post is low enough so that it can easily behandled; and this method of providing vertical adjustment for anysurface inequalities is superior to the separate jack members now in usebecause it secures a greater extent of adjustment and also performs thedual function of post and jack combined.

Floor sections may be provided in place of the loose boards ordinarilyused in scaffolding as shown in Figs. 9 to 11. These floor sections aretriangular in shape, conforming to the dimensions of the brace members,which, as shown in Fig. 9 and previously described, ordinarily consistof two braces 28 and 29 forming the legs of a right angle isocelestriangle with a third brace 2"! forming the hypotenuse thereof. Thefloor section 53 fits within this combination of braces and consists ofthe necessary number of boards 54, assembled in the form of a rightangle triangle to the periphery of which is bolted a Z-bar 55. Fig. 10,which is a section taken across the diagonal brace 21 where two floorsections come together, shows that at this point these Z-bars 55 willstraddle the brace 21 and form a channel around its upper portion,whereas on the outer braces 28 and 29 the Z-bar will cover onlyapproximately half of the surface of the upper portion of the brace sothat similar floor sections may be added as the scaffolding is expanded.By the use of floor sections of this type the strength, rigidity, andsafety of the scaffolding is materially increased. 7

Figs. 12 to 15 give a few instances of the manner in which the few basicelements of the scaffolding of the present invention may be assembled,and exemplify the wide range of constructions that may be secured. Fig.12 shows that when it is necessary to build a scaffold to conform to acurving wall or tank, adjacent braces 56 and 51 lying along the wall ofthe structure can be placed at an angle to each other instead of forminga straight line, by merely leaving out a connecting brace which wouldordinarily be placed as, for example, between the posts 58 and 59 androtating the brace 51 in relation to the post 60. In this manner, astructure having practically any curvature can be surrounded byscaffolding.

In erecting a scaffold it frequently becomes possible to extend thestructure horizontally without the necessity of providing verticalsupports to the ground at the junctions of each of the horizontalmembers, but at the same time retaining a comfortable factor of safetyfor the pr'evailing load conditions.

This arch or bridge construction is assembled by first securing thesebrace members 62 between the plates ll and 18 of the main vertical posts19 and 89. Then, by inserting the filler members of posts 43, shown inFig, 8, in the post section of the braces 62, the structure may be builtupwardly by incorporating standard braces 81 and 82 and furtheroutwardly by the use of additional braces 62. At the center of the arch,the abutting post sections 83 and 84 are secured together by means ofbolts 85 extending through holes provided for this purpose. Variousother combinations of braces may be used to vary the length of the spaceof this arch construction; and, of course, it is also possible to usethe brace member 62 to form an outrigger or overhanging section ofscaffolding which is extremely useful in situations where there areirregularities in the upper portions of the structure around which thescaffolding is being erected, which irregularities are not present atground level.

The post 26, shown in Fig, '7, can be used as the uprights of a baseportion of a tower, as shown in Figs. 14 and 15; namely, by securinghorizontal braces thereto between the circular.

plate 6! of a foot and a sleeve 31, this plate 6| being provided with aseries of holes similar to the holes in the other plates 33 and 35previously described. If it is desired to have a readily movable towercasters 65 are attached to the lower end of the posts 28 by the samebolt which holds the foot 24 in position, In order to give maximumrigidity at the base of the tower the horizontal braces 66 which formthe sides thereof are mounted in an'inverted position, which is possiblein any assembly of these scafiold elements, so that their horizontalmembers 6 3 are positioned adjacent the floor or other surface uponwhich the tower rests, while the diagonal brace 6'! is assembled in itsordinary position to give a bracing effect across the top portion of theposts. The tower may then be built to the desired height by simplyadding other elements of this scaffolding such as upright members 2! andsuitable braces.

Although the method preferably used in assembling horizontal braces to apost employs the movable sleeve 37 which clamps the horizontal bracessecurely in position, it is possible, as shown in Fig. 16, to use fixedcircular plates 68 and 69 which are welded to a post 10 in suchpositions that a clearance is provided between the lower surface of theupper plate 68 and the top of the horizontal member 12 of the brace, sothat the vertical member H of such brace is at all times retained inposition, but may be readily removed therefrom by moving such verticalmember upward, outward and then downward. The brace member shown in thisview functions as, and is termed a catwalk support, although it may alsobe used to advantage as the boom of a hoist for bringing material to theworkmen on the scafi'old.

Modification of the elements disclosed herein is permissible withoutdeparting from the spirit of this invention, as defined by the followingclaims.

I claim:

1. A scafiold comprised of vertical posts of tubular construction andhorizontal braces extending between said posts, said horizontal bracesbeing composed of vertical members positioned adjacent said posts andconnected to a horizontal member extending therebetween, and means forsecuring said horizontal braces to said vertical posts comprising afixed plate mounted on said posts, said plateihaving holes thereinadapted to receive. the lower ends -of said vertical members of saidhorizontal'braces, asimilar plate adapted to receive theupper ends ofsaidvertical mem bers,-said latter platebeing mounted for limitedvertical-movement so that at the upperlimit-of such movement saidhorizontal brace may be' detached from said posts or attached thereto.

2. A scaffold comprised of vertical posts of tubular construction andhorizontal braces ex-.

tending between said posts, said horizontal braces being composed ofvertical member positioned adjacent said posts and connected to ahorizontal member extending therebetween, and means for securing saidhorizontal braces to saidvertical posts comprising a fixed plate mountedon said posts, said plate having holes therein adapted to receive thelower. ends of said vertical members of said horizontal braces, asimilar plate adapted to receive the upper ends of said verticalmembers, saidlatter plate being secured to a sleeve, said sleeve beingmounted on said post so as to be vertically'movable with relationthereto, the upper extent of such movement being such that in thisposition said, horizontal brace'remainssecured to said vertical postsbut may be readily removedtherefrom. I

3. A scaffold comprised of vertical posts 'of tubular: construction andhorizontal braces extending between said posts, said horizontal bracesbeing composed of vertical members positioned adjacent said posts andconnected to a horizontal .member extending therebetween, and means forsecuring said horizontal braces to said vertical posts in triangularrelationship comprising a fixed plate mounted on said posts, said platebeing provided with a series of holes spaced about the center of saidpost adapted to receive the lower ends of said vertical members, asimilar plate adapted to receive the upper ends of said verticalmembers, said latter plate being mounted for limited vertical movementso that at the upper limit of such movement said horizontal brace may bedetached from said posts or attached thereto.

4. A scafiold comprised of vertical posts of tubular construction andhorizontal braces extending between said posts, said horizontal bracesbeing composed of vertical members positioned adjacent said posts andconnected to a horizontal member extending therebetween, and means forsecuring said horizontal braces to said vertical posts comprising afixed plate mounted on said posts, said plate having holes thereinadapted to receive the lower ends of said vertical members of saidhorizontal braces, a similar plate adapted to receive the upper ends ofsaid vertical members, said latter plate being mounted for limitedvertical movement so that at the upper limit of such movement saidhorizontal brace may be detached from said posts or attached thereto,some of said posts being of fixed length, others of said posts beingadjustable in length so that said horizontal braces will lie in the sameplane independent of ground conditions, said adjustable posts comprisingan outer casing, a jack screw contained within said casing, and means torotate said jack screw whereby vertical movement will be imparted tosaid casing.

5. A scaffold comprised of vertical posts and horizontal bracesextending between said posts, said horizontal braces being composed of amain horizontal member, vertical members connected to each end of saidhorizontal member so as to project above and below said horizontalmember, the extent of such projection of said vertical members abovesaid horizontal member being greater than the extent of such projectionbelow said horizontal member and means for securing said horizontalbraces to said vertical posts comprising spaced plates carried by saidposts, said plates being provided with a series of holes adapted toreceive the upper and lower ends of the vertical members of saidhorizontal braces. I

6. A scaffold structure comprised of vertical posts of tubularconstruction connected by a series of horizontal braces, characterizedby said horizontal braces each being composed of a main horizontalmember, and vertical members connected to each end of said horizontalmember, spaced plates carried by said posts, said plates being providedwith means for engaging the upper and lower ends of said verticalmembers of said form of horizontal braces, thereby securing such bracesto said posts, a second form of horizontal braces each being composed ofa main horizontal member, a similarvertical member connected to one endthereof and a tubular post section connected to the other end thereof,said second form of horizontal braces being similarly secured to saidposts by the interengagement of the vertical members thereof with saidspaced plates, and other posts carried and supported by said postsection of said second form of horizontal braces, whereby an archconstruction may be employed in'said scaffold structure.

'7. A system of scaifolding composed of vertical posts, a series ofhorizontal braces of a plurality of different lengths of predeterminedrelation-- ship wherein each next longer brac of said series bears therelationship to the next shorter brace of said series of sin 45 where a:is substantially equal to the length of said next shorter brace, saidhorizontal braces being composed of a main horizontal member, verticalmembers connected to each end of said horizontal member so as to projectabove and below said horizontal member, and spaced plates carried bysaid posts, said plates being provided with a series of holes adapted toreceive the projecting upper and lower ends of the vertical members ofsaid horizontal braces, whereby said posts of said system of scaffoldingmay be interconnected by suitable lengths of horizontal braces from saidseries.

8. A system of scaflolding composed of vertical posts, a series ofhorizontal braces of a plurality of different lengths of predeterminedrelationship wherein each next longer brace of said series bears therelationship to the next shorter brace of said series of sin 45 where a:is substantially equal to the length of said next shorter brace, andmeans whereby said horizontal braces may be independently detachablyconnected to said vertical posts in polygonal relationships, comprisingspaced plates carried by said posts, said horizontal braces beingsecured to said posts between a pair of said spaced plates.

NOLAN S. BLACK.

